1. Field of the Invention
The present invention relates to animal cages and, more particularly, relates to a flood prevention system for use in a ventilated small animal cage and to a cage having a flood prevention system.
2. Discussion of the Related Art
Ventilated cages are widely used in research facilities for housing lab animals such as mice and rats. The cages typically are provided in a cage and rack system in which a number of rows of cages are mounted on stacked shelves. In order to prevent the air in each cage from contaminating adjacent cages, all of the cages of the typical system of this type are ventilated using a common air supply duct that supplies air to the cages and a common exhaust manifold that draws air out of the cages, thereby leaving a slight positive pressure in the cages. The animals therefore remain isolated from one another to prevent the transfer of diseases. Systems of this general type are disclosed in U.S. Pat. Nos. 5,954,013; 5,349,923; and 5,148,766, all of which are assigned to Lab Products, Inc.
The cages may be supplied with drinking water either by individual water bottles or by a water supply manifold and a plurality of animal watering valves, one of which is accessible from each cage. When a water manifold and animal watering valves are employed to supply drinking water to the animal, each cage may be coupled to both the air supply duct and the water supply manifold by a common docking assembly that extends into the front wall of the cage.
Water supply valves and water bottles sometimes leak, potentially flooding the bottom of the cage and endangering the animals housed in the cage. If the cage is provided in a cage and rack system, the flooding danger extends to cages adjacent the cage with the leaking water bottle or watering valve. Prior known-cages lacked any measures to prevent cages from flooding and also lacked adequate measures to channel any water that leaked from a watering valve or bottle away from the cage. The need therefore has arisen to provide a drain for draining water from a leaking water supply valve or water bottle away from a cage, thereby preventing the cage from flooding. However, in order to minimize or prevent the air in the cage from contaminating the adjacent cage, an acceptable flood prevention system should not unnecessarily destroy the atmospheric integrity of the cage by allowing it to be contaminated with room air.
Even an adequate drain would not solve all problems associated with a leaking water bottle or watering valve. Most cages have wood chips or another water-absorbent bedding strewn about their floors. This bedding may become saturated if a water bottle or watering valve leaks and remain damp for a substantial period of time thereafter, even if all standing water were to be drained from or otherwise removed from the cage. Wood chips are particularly problematic because they act as wicks to draw water from the flooded portion of the cage to other portions that would otherwise remain dry. Damp bedding poses a substantial source of discomfort to animals housed in the cage and may pose hypothermia and other health risks to the animals. These risks are particularly high in ventilated cages because the animals may be chilled by airflow through them. The need therefore has arisen to provide a safe haven that remains dry even if the bedding in the cage becomes saturated from leaking or spilled water.